All forms of smoking, including passive, are bad for the heart

All forms of tobacco exposure, active smoking or by the chiquant and passively increase the risk of myocardial infarction up to triple, shows a study published in the "Lancet".

Various studies have shown that smoking tobacco increases the risk of heart disease. Most of them have been conducted in developed countries and few large studies have observed the effects of tobacco in other geographical regions.

The INTERHEART case-control study was conducted among 27,089 people (12,461 cases and 14,637 controls infarction) in 52 countries (Asia, Europe, Middle East, Africa, Australia, North and South America). The risk of myocardial infarction was evaluated in smokers and former smokers, according to the type of tobacco used (including smokeless tobacco, chewing tobacco or snuff), the amount consumed and the potential exposure to smoking liabilities. The risk was then adjusted for other cardiac risk factors related to lifestyle, such as diet and age.

The researchers found that the consumption of tobacco in any form, including hookah, popular in the Middle East, or beedi used in Southeast Asia (tobacco rolled in a sheet of dried plant or tied with string) is dangerous.

Compared with people who never smoked, smokers have a three times greater risk of myocardial infarction. Even those who smoked relatively little (eight to ten cigarettes per day) are exposed to a doubled risk of heart attack.

However, the risk decreases with time after smoking cessation. Among light smokers (less than ten cigarettes per day), is no longer observed excess risk three to five years after smoking cessation.

In contrast, heavy smokers or moderate smokers (more than twenty cigarettes per day), a residual risk is retained about 22% twenty years after stopping.

The team also found that exposure to secondhand smoke increases the risk of myocardial infarction in both former smokers and in people who never smoked. The most important (at least 22 hours per week) exposure level appeared associated with an increased risk of heart attack by 45%. An exhibition of more than one hour per week in non-smokers has been associated with an increased risk of 15%.

In addition, chewing tobacco double the risk of heart attack and smokers who chew more people are exposed to a fourfold risk.

Young male smokers are most affected and older women the least.

"It would dissuade people from using tobacco, in whatever form, including different ways of smoking and chew it or inhale passively to prevent cardiovascular disease," the authors conclude.